1. Field of the Invention
The present invention relates to a digitizing method by which positional data are sequentially fetched while profiling the configuration of a model, and more specifically, to a digitizing method capable of creating NC data by which the flagging of a corner is reduced.
2. Description of the Related Art
FIG. 5(a) is a diagram explaining a conventional digitizing method, wherein a stylus 2 is moved along a model 4 and respective points P11, P12, . . . are sequentially sampled from a previous output point P10 at predetermined intervals. Therefore, the distance from the middle point of a straight line, connecting the previous output point P10 and a present sampling point, to an intermediate point among the sampling points sampled up to this time is determined, and when this distance exceeds a preset tolerance value, the sampling point is designated as an output point.
In the figure, the distance l 16, which is determined when sampling has been executed up to a sampling point P16, satisfies this condition, and thus P16 is designated as an output point and NC data approximating a straight line between the output points P10 and P16 is output.
Nevertheless, the conventional method has a drawback in that the change of a configuration is determined by the middle point among the sampling points.
FIG. 5(b) is a diagram showing a case in which digitizing is executed by profiling a model 5 having a corner 5a, wherein a stylus 2 is moved along the model 5 and respective points P21, P22, . . . are sequentially sampled at predetermined intervals from a previous output point P20.
As can be seen from the figure, the distances determined by the above method with respect to sampling points P21 to P25 located in front of the corner 5a are zero and thus they are not designated as an output point. Instead, a sampling point P26 located after the corner 5a and having a distance l 26 exceeding the tolerance amount is first designated as an output point, and as a result, NC data is created based on the straight line connecting the output points P20 and P26, which causes a flagging of the corner.